Stabilization of oils and fats



doom UNITED STATES PATENT OFFICE STABILIZATION GF OILS AND FATS WilliamD. Richardson, Donald P. Grettie, and Roy C. Newton, Chicago, Ill.,assignors to Swift & Company, Chicago, Ill., a corporation of IllinoisNo Drawing. Application May 12, 1931, Serial No. 536,942

6 Claims. (CI. 9986) age and distribution in the package, but also whenused in the manufacture of food products quality of pure lard butapparently has little or such as crackers and other bakery products, inno efiect of retarding rancidity of lard in'pie which, or in themanufacture of which, water crusts. Similarly the dimethyl ether ofpyroor aqueous liquids are used. gallo-l is'an effective anti-oxidantin' pie crusts,

1o Fats and oils of commerce are subject to de- For practical use in anedible product the antil0 terioration in quality due to oxidation. Thisdeoxidant or stabilizing agent added to the lard terioration results inlarge losses in the manufacor other edible oil or fat should benon-toxic and ture and distribution of shortenings and other should beof such a nature that it will be elimifat-containing products. Theedible oils and nated properly when taken internally as a con-.

fats on deterioration become non-edible and must stituent of food.Phenols are widely distributed 15 be used for non-edible purposes; whileedible in nature, occurring in many natural food prodfat-containingproducts likewise become nonucts in small quantity; and thephysiological edible on deterioration of the fat constituent. Inmechanism for handling small quantities of phethe manufacture ofcrackers and other bakery nols is well known. The water insolubility ofproducts Where fats are used and where the prodthe phenolic derivativesemployed in the present 20 ucts are kept for considerable periods oftime, invention is an aid in discarding and elimination there is a veryconsiderable hazard and frequentof the phenols, since it limits theamount ably very considerable loss due to this oxidation or sorbed fromthe digestive tract. In general the rancidity of the fat contained insuch products. stabilizing agents to be of general application We havefound that it is possible to stabilize should be odorless, tasteless andcolorless.

fats and oils not only in the package during dis- The class of compoundswhich we have found tribution but also in the food products, such asparticularly suitable for use with edible oils and bakery products, inwhich the oils and fats are fats are condensation products of phenolswith used, by incorporating in the oils and fats a ketones or aldehydes.We have found the consmall amount of a suitable stabilizing agent.densation product of pyro all gl gng ace It has heretofore been proposedto increase the e e a d an unusually stability of oils and fats while instorage and in assets/e tile rvation of oils or the package byincorporating small amounts of fats, not only in a pure state, but alsoafter mixphenols therein; but such phenols are more or ing in pie crustsand other bakery products. We

less soluble in water and, due to this fact, they have obtained verysatisfactory results by dis- 35 are extracted from the oil or fat whenthe shortsolving quantities as low as 0.01% or less of such ening ismixed with other ingredients containing condensation products in lard orother fats. This moisture; and this is especially-true if and whencondensation product can be made by dissolving the other ingredients arealkaline or contain 2.1- the pyrogallol in slightly more than molecular40 kaline constituents. Thus, pyrogallol and pyroquantities of acetoneand passing in dry hydrogen 5 ecatechin added in small amount to lardwill imchloride. Presumably this product is gallacetoprove the keepingquality of pure lard to a very nin, but we have not established itschemical considerable extent; but they have little or no identity.effect in stabilizing the lard and retarding ran- In general, thesubstances which are insoluble cidity when it is incorporated in piecrusts. or least soluble in water appear to be most effec- We have foundthat substituted poly-phenols tive in stabilizing the oil or fat productafter and poly-phenol derivatives which are soluble in it has beenincorporated in a mixture of other the oil or fat and which areinsoluble or practiingredients as in the case of the manufacture callyso in water are effective not only in staof pie crust, for example. Thecondensation 5O bilizing the oil or fat during storage and in theproduct of pyrogallol and acetone is almost enpackage but also stabilizethe oil or fat and retirely insoluble in water but quite soluble in oilstard oxidation and decomposition after they have or fats. When pure orin a purified state it has been used as shortening in pie crusts orother apparently no toxic properties. It produces, bakery products. whenmixed with lard, in quantities as small as Among the phenolicderivatives which we have 0.01%, an increase in the keeping qualities of55 This invention relates to improvements in the stabilization of oilsand fats, and more particularly stabilization of edible oils and fats,whereby the oils and fats are stable not only during storfound suitableare poly-phenols, especially orthoand para-poly-phenols which containsubstituting groups such that the phenol derivatives are insoluble orpractically so in water. For example, while pyrocatechin will improvethe keeping 5 the lard, under certain tests, up to 1000% or more.

Other stabilizing agents which we have found effective in stabilizinglard and other oil and fat products, both in a pure state and in piecrust, etc. are the following:

Stearclated pyrogallol, CsH2(OI-I)3CO.C17H35 Pyrogallol dimethyl etherQuinol-anisaldehyde condensation product 1.4 andl.5-dihydroxy-naphthalenes The amounts of the difierent stabilizingagents to be used can be varied somewhat, but in general only a smallfraction of 1% will be used. The stabilizing agents are incorporated inthe oil or fat by dissolving in the oil or fat in which they aresoluble. These substances, however, contain groups or groupings whichrender them insoluble in water or practically so, so that they arethereby made efiective in stabilizing the oil or fat against rancidityin the presence of moisture and other ingredients, such as the proteinconstitutents present in bakery products.

The stability of edible oils and fats is commonly determined byso-called accelerated aging tests carried out at relatively hightemperatures to produce in a short time changes such as would inpractice require far longer periods of time, and determining, by suchhigh temperature tests, the time necessary to produce a definite odor ofrancidity.

The criterion of rancidity which we have used to demonstrate theimproved keeping qualities of oils and fats stabilized according to thepresent invention is that of odor and taste after subjection of .asample of incubation at 70 C. for a period of time necessary to producea typically rancid odor. In comparing the stability of the fatsthemselves, a 50 gram portion of the sample is weighed out and placed ina small glass container of about 250 cc. capacity having a loose fittingcover. This container is then placed in an incubator which has beenregulated definitely to 70 C. and allowed to remain until dailyinspections show it to be rancid to the senses of taste and smell. Thetime required for the development of this rancidity is taken as ameasure of the resistance of the fat to rancidity.

In testing the stability of the fat after having been made into bakeryproducts, etc., the fat is used in the manufacture of a small lot of piecrust under carefully controlled conditions to prevent contaminationwith other fats or metals which promote oxidation. Care is further takento use entirely analogous ingredients for each sample of a series undercomparison. These pie crusts are then baked out, being careful that allof the series in a single comparison are in the same oven at the sametemperature for the same length of time. The baked pie crusts are thencrumbled and placed in 250 cc. containers with loose fitting covers andincubated at 70 C. until definite rancidity develops. Again the lengthof time required to develop this rancidity is a measure of the stabilityof the fat.

We claim:

1. A baking composition comprising stabilized edible oils and fats whichare stabilized during storage and distribution and when subsequent!yused with water in the manufacture of bakery products, said oils andfats having incorporated therein a fraction of 1% of a non-toxic andsubstantially odorless and tasteless amino-free phenol derivativesselected from the group consisting of polyphenols, substitutedpolyphenols, and condensation products of polyphenols with ketones oraldehydes, said polyphenol derivative being soluble in the oil or fat,but having such insolubility in hot water and stability at hightemperatures that it will remain in the oil or fat when used with waterin the manufacture of bakery products, and stabilizes the same duringsuch use and in the resulting bakery product.

2. Bakery products containing therein stabilized oils or fats,stabilized by the presence therein of a fraction of 1% of a non-toxicand substantially odorless and tasteless amino-free phenol derivativeselected from the group consisting in polyphenols, substitutedpolyphenols,

and condensation products of polyphenols with ketones or .aldehydes,said polyphenol derivative being soluble in the oil or fat, but havingsuch insolubility in hot water and stability at high temperatures thatit remains in the oil or fat in :5.

said bakery products and stabilizes the same.

3. The process of stabilizing oils or fats which comprises incorporatingtherein a small amount of .a condensation product of pyrogallol andacetone which is substantially insoluble in water but soluble in the oilor fat.

4. The process of stabilizing oils or fats used in food products inwhich, or in the manufacture of which, water is used, which comprisesincorporating in the oil or fat a small amount of a condensation productof pyrogallol and acetone, and incorporating the resulting oil or fat inthe food products.

5. Stabilized oils or fats containing therein a small amount of acondensation product of pyrogallol and acetone substantially insolublein water but soluble in the oil or fat.

6. Food products in which, or in the manufacture of which, water isused, said products containing therein oils or fats stabilized by thepresence therein of a small amount of a condensation product ofpyrogallol and acetone.

WILLIAM D. RICHARDSON. DONALD P. GRETTIE. ROY C. NEWTON.

